A057911 Numbers k such that 2*3^k + 5 is prime.

0, 1, 2, 3, 4, 5, 8, 9, 22, 23, 28, 37, 49, 53, 59, 74, 83, 149, 183, 577, 993, 1335, 1777, 7077, 8518, 8775, 12193, 20225, 21544

Offset

1,3

Links

Table of n, a(n) for n=1..29.

Mathematica

Do[ If[ PrimeQ[ 2*3^n + 5 ], Print[ n ] ], {n, 0, 2500} ]

Prog

(PARI) is(n)=ispseudoprime(2*3^n+5) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Cf. A057910 (2*3^k - 5 is prime).

Sequence in context: A120430 A295033 A152606 * A085266 A280431 A056804

Adjacent sequences: A057908 A057909 A057910 * A057912 A057913 A057914

Keyword

nonn,more

Author

Robert G. Wilson v, Nov 16 2000

Extensions

First term 0 inserted by Georg Fischer, Aug 01 2019

a(24)-a(28) from Jinyuan Wang, Jan 20 2020

a(29) from Michael S. Branicky, Apr 24 2023

Status

approved